1. Field of the Invention
This invention relates generally to fresh water production, and more particularly to an apparatus, system and method for electrostatic desalination and water purification.
2. Description of Related Art
One of the growing problems facing mankind in the 21st century is the ability of the earth to sustain an ever growing population. Natural resources such as food and water supplies are being depleted or damaged by the activities of man in ways that impact all of humanity, particularly those that live in poor regions of the world.
Clean drinking water is essential for all life to exist on this planet. In addition, water is necessary to grow crops and sustain food production. Unfortunately our fresh water resources have not been protected in ways that will ensure that future generations will have adequate fresh water supplies. Fresh water has been overused, aquifers have been depleted, and pollution has spoiled water quality in many regions of the world. Fresh water supplies were treated as a never ending resource; unfortunately, this is not reality, and water shortages as well as the spread of disease and sickness through contaminated water is a major problem of this century. Technical advances are needed to provide adequate water supplies to sustain life in the future. These advances may include techniques to clean polluted water as well as techniques to utilize the earth's available water in ways that have heretofore been impossible.
According to the NASA Earth Observatory website www.earthobservatory.nasa.gov, 75 percent of the earth's surface is covered by water, with 96.5 percent being in the global oceans. Unfortunately, ocean water is not drinkable in its present form. This has been a monumental difficulty throughout humanity, and the frustration of having plentiful, albeit non-drinkable, water is described well in the famous line from Samuel Taylor Coleridge's The Rime of the Ancient Mariner—“Water, water, everywhere Nor any drop to drink”.
There are techniques to extract fresh water from salt water, one of the oldest being boiling or distillation. As salt water is boiled, the steam leaving the salt water is condensed, the steam being essentially fresh water. This technique was known by mariners hundreds of years ago, and still manifests itself in commercial flash distillation plants. Distillation is an energy intensive process due to the heat required. This makes distillation not only expensive, but also contributes to the growing problem of carbon dioxide emissions, as well as other pollutants, and their subsequent impact on the environment. Reverse Osmosis is a fairly recent technique that has gained widespread attention as an alternative to distillation. This process is also energy intensive due to the pressures needed to move water through the reverse osmosis membrane.
There have been other attempts to desalinate ocean water including freezing, various chemical processes, and others.
In the 1960's, Yukichi Asakawa observed that the evaporation of water can be increased or assisted by an electric field. In a 1967 symposium this information was presented to the Japan Society of Mechanical Engineering.
In U.S. Pat. No. 5,203,993 Method and Apparatus For Removing Salt From Sea Water, now expired, Arbisi describes an apparatus and method that used a supply tank containing salt water where bubbles are discharged in the chamber and a crossflow of air is applied along with an electric field to obtain water of lesser salinity than the starting salt water. In the '993 patent, techniques to further reduce the salinity of the product water are disclosed, including reverse osmosis and electrodialysis desalination. It appears from the disclosure that the apparatus of Arbisi was not able to generate fresh water without the addition of a secondary system such as reverse osmosis or electrodialysis desalination. In addition, the apparatus of Arbisi uses supply tanks and collection tanks, making the apparatus unsuitable for continuous processing of fresh water. These and other shortcomings are solved by the present invention and the various embodiments described herein. The entire disclosure of U.S. Pat. No. 5,203,993 is incorporated herein by reference.
It is known that an electric field is capable of interacting with water vapor. U.S. Pat. No. 6,302,944 to Hoenig describes an Apparatus For Extracting Water Vapor From Air. The entire disclosure of this patent is incorporated herein by reference.
Therefore, there currently exists an unmet need for a system to remove impurities from sea water to make it fit for human consumption without the need for massive energy consumption and its associated pollution, carbon emissions, and other environmental impacts. It is expected that this unmet need will continue to increase with the rise in world populations and the increase in global temperatures and associated water shortages. There is further an unmet need to provide a system to convert sea water into fresh water that can be economically scaled in size to provide both small systems that can be economically operated in poor regions of the world as well as larger commercial systems that can supply fresh water on a municipal or regional basis. It is thus an object of the present invention to provide an apparatus, system and method for desalination and purification of water, in particular but not limited to, the desalination of sea water. It is another object of the present invention to provide an apparatus, system and method for desalination and purification of water that requires very little energy consumption. It is yet another object of the present invention to provide an apparatus, system and method for desalination and purification of water that has very low maintenance requirements and is simple to operate. It is yet another object of the present invention to provide an apparatus, system and method for desalination and purification of water that operates on either a continuous or a batch process. These and other objects of the present invention will be further brought to light upon reading this specification and claims and viewing the attached drawings.